Farmers have long wrestled with the question of when a field of corn is ready to be harvested. Corn loses moisture after it reaches the point of maturity. Corn that is harvested too early has a high moisture content, and cannot be stored without spoiling. The operators of grain elevators where many farmers bring their harvested corn may therefore refuse to store corn whose weight attributable to water, or moisture content, is 16% or higher, for fear it will spoil everything in the store. Instead, the farmer is charged a fee for the operator to “dry down” the corn to an acceptable level by heating the corn to remove excess moisture. The profit margin on corn can be so slim that the drying-down fees to bring the moisture content of “under-dried” corn down even slightly may erase the farmer's profits, or cause the farmer to suffer a loss.
Yet there are also disadvantages to “over-drying” by letting corn stand in the field too long before harvesting. Each day the corn goes unharvested increases losses due to lodged or dropped ears, and increases the risk that pests, hail, tornadoes, or other adversity will damage or destroy the crop. Moisture loss also decreases sale weight. Over-dried kernels are also more brittle and prone to break, resulting in a lower quality rating. Finally, harvesting may also be less efficient on over-dried corn, as combines work best on corn having a moisture content of 20-22%.
While the drying-down fees associated with under-drying are quantifiable and predictable, the above-mentioned costs associated with over-drying are not as apparent. Psychological aversion mechanisms may therefore explain why many farmers err on the side of over-drying by leaving their crops for longer than necessary, and suffer the associated costs.
Current methods of determining the moisture content of corn involve the use of electronic moisture meters, or comparing the weight of the corn before and after it is heated in an oven. In addition to being cumbersome, such techniques do not predict an optimum time to harvest the corn, nor do they take into account the unseen attrition costs of over-drying the corn.